To detect genetic mutations in bud sport cultivars of peach, RLGS (restriction landmark genomic scanning) analysis was performed on 7 putative bud sport mutant cultivars after SSR (simple sequence repeats) analysis for identifying false-mutants. Three cultivars, ‘Yawata Hakuho’, ‘Odoroki’, and ‘Kanoiwa Hakuto’, postulated to be bud sport mutants, were confirmed as false-mutant cultivars. This suggests that other false-mutant strains of peach are also likely to be registered with the Plant Variety Authority as bud mutant cultivars. A stable RLGS profile of peach, obtained using NotI as a landmark enzyme, showed about 400 spots in a single experiment. Comparing the profiles between mutant and original cultivars, polymorphic spots were discovered in 2 mutatnt cultivars, ‘Gyosei’ and ‘Nagasawa Hakuho’, but were not detected by SSR analysis. RLGS was thus considered to be an effective method to detect very small genomic variations in mutant strains.